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<body class="ignore-math"><article class="example example-like"><div class="displaymath process-math" data-contains-math-knowls="">
\begin{equation*}
\frac{\textrm{d}^2y}{\textrm{d}x^2}+\frac{\textrm{d}y}{\textrm{d} x}+x=0,
\end{equation*}
</div>the highest order of derivative is <span class="process-math">\(2\text{,}\)</span> thus it is called second order ODE. Generally, an ODE may take the form<div class="displaymath process-math" data-contains-math-knowls="">
\begin{equation*}
F(x, u(x), u^{\prime}(x), \cdots, u^{(n)}(x))=0.
\end{equation*}
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